Process for producing fibrous material from rice-straw.



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JUSTIN KAY TOLES, OF SAN FRANCISCO, CALIFORNIA, ASSIGNOR TO UNION FIBRECOMPANY, OF WINONA, MINNESOTA, A CORPORATION OF MINNESOTA.

PROCESS FOR, PRODUCING FIBROUS MATERIAL FROM RICE-STRAW.

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Specification of Letters Patent.

Iatentcd July 31, 1917.

No Drawing. Application filed March 1, 1915, Serial No. 11,378. RenewedJune 15, 1917. Serial No. 175,039.

To all whom it'moy concern.

Be it known that I, JUSTIN KAY ToLEs, a citizen of the United States ofAmerica, residing at San Francisco, county of San Francisco, State ofCalifornia, have invented a certain new and useful Process for ProducingFibrous Material from Rice-Straw; and I do hereby declare the followingto be a full, clear, and exact description of the invention, such aswill enable others'skilled in the art to which it appertains to make anduse the same.

This invention relates to a novel and improved process for producingfibrous material from rice straw.

At present no use is made of rice straw though many unsuccessfulattempts have heretofore been made to treat and prepare it for practicaluse and commercial purposes. Annually in the States of California, Texasand Louisiananot to mention other parts of the United States-hundreds ofthousands of tons of rice straw are wasted or destroyed, usually byburning, solely because the rice straw cannot be marketed before theinvention of some means or process whereby the rice straw can be treatedto change its state or condition so that it can be utilized practicallyand commercially. Heretofore strawboard, wall-board, refrigerator felt,insulating lining, roofing-material, etc., has been made of materialscombined with a material, such as flax straw, which latter furnishes thefibers that naturallly'bind together and act as a bond for the othermaterials. Besides other objections to-the use of flax straw as juststated, are the highly absorbent nature of the flax fiber and itsexpense which narrows its field for application commercially incompetition with other products.

The main object of this invention is to provide an alkaline, or noveland improved pmccss whereby it becomes possible to fiberize and thusutilize the cheap and abundant supply of rice straw which now is wastedand has little or no commercial value.

In carrying out the process the rice straw is placed in a causticsolution preferably consisting approximately of two parts of lye, onepart'of permanganate of potash,

and one hundred parts of water. The rice straw in the solution is boiledfrom'one-half" to one hour,,in order to break down or destroy therefractory substances which on- 'shroud the fibers of the rice straw;after which the rice straw is freed of the solution, preferably bypassing it through squeeze rollers, and then it is washed-in water,preferably boiling; after which it is given a bath in a two percent.approximatesulfuric acid solution to neutralize any part of thesolution still remaining thereon. Then it is freed from the acidsolution, preferably by passing it 7 through squeeze rollers, and placedin a solution of suitable strength of any commercial oXid, such asalumina hydroxid, oXid of iron, or any of the chromic oxids, after whichit is freed of the last solution, preferably by squeezing and washing itin Water. The reactive acid oXid bath fixes and strengthens the fibersand preserves them against further attack by atmospheric oXids.

This process disintegrates the rice straw to its fibrous constituentsand produces from the rice straw a fibrous material in which the fibersare not only light in weight, but they are also strong, flexible, highlyresistant to moisture, and have excellent-binding and felting qualities.

The fibrous material produced by the above process constitutes a'cheapcommercial product which is adapted to be mixed or combined with otheringredients or materialsunder pressure, and heat in some cases-as abasis to form various commercial products, such as straw-board,linoleum, wall-board, panels, refrigerator felt, insulating or sounddeadening lining, roofing material, tiles, etc.

The process which has been particularly described admits ofsubstitutions and variations of ingredients and operations, whereforethe right is reserved to all such substitutions and variations ofingredients and operations as are the equivalent of those which arementioned in the appended claims.

Iclaim:

l. A process for fiberizing rice straw, which consists in first boilingthe'rice straw in an alkaline solution in order to break down thesubstances which enshroud the tion, and then subjecting it tothe actionof a solution of any commercial oxid.

2. A process for producing fibrous material from rice straw, whichconsists in first boiling the rice straw in a solution of lye,

permanganate of potash, and water, then Washing the rice straw in Wfltl,then giving the rice straw a bath in an acid solution, and thensubjecting the rice straw to the action of a solution of any commercialoxid.

8. The herein-described process for pro clucing fibrous material fromrice straw, which consists in boiling the rice straw in e solutionconsisting approximately of two parts of potash, one part ofpermanganate of potassium and one hundred parts of Water, said boilingto continue from one half to one hour according to the strength of saidsolution otter which the rice straw is freed from seicl solution andWasher in boiling meter, en the rice 1s A, H, LKDDERS,

